Find the new price?

[Phisics]

Aoife is shopping for a New TV.
The TV she wishes to buy sells from $550.The TV is on ' special offer' in three different shops .
Shop offers 20 % off the usual price , of the TV. Find the special offer price, I can't get it can someone help me ?
Thanks in advance

 

[Deleted member 4993]

If the original price of the TV was $100 and the special offer is 20% off - what is the selling price of the TV?